Guild created Lore ;)
And theres this bit found in a scroll owned by the Priory
“The Vanguard was created in 1318 AE by Balor O Suilamhain,a human necromancer that was said to have been touched by Grenth as a child as evidenced by the potencil ability he had,he sensed the growing threat of Zhaitan´s Risen,who had taken from him everyone he ever loved and set him on the path of necromancy to try and bring them back from the Mists,so he called in some favours on soldiers,adventurers and scholars alike he met on his travels,like the charr gladium Azrael Snowcoat,the norn warrior Ulfrith Drakenvold and many others that answered the call.They didnt identify themselves with the views of the Vigil,the Priory and the Order of Whispers,and what started as a Guild like many others went on to become famous around Tyria!
The Vanguard has its home on “The Druken Sword Inn” in Lions Arch,tho they have a small settlement in Southsun Cove to train drills and keep a small garrison ready for various missions.
They are always in motion,recruiting many more to form the Vanguard Blood Order,the first blood spilled on the front line."